Objectives: This systematic review aimed to examine hip rotator range of motion (ROM) and strength values across athletic, injured, and non-active populations, and to determine how these values differ when measured at different hip flexion angles. Methods: A systematic literature search was conducted in accordance with PRISMA guidelines across six electronic databases (PubMed, Scopus, Web of Science, SPORTDiscus, CINAHL, and Medline) from inception to June 2025. Eligible studies included observational, cross-sectional, case-control, or randomized controlled trial (RCT) studies that quantitatively assessed hip IR/ER ROM and/or strength in defined population groups (athletic, injured, or non-active). Two reviewers independently screened titles, abstracts, and full texts, extracted data on study design, population characteristics, measurement methods, and outcome variables, and assessed risk of bias using an established tool. Discrepancies were resolved by a third reviewer. Results: 11 studies met the inclusion criteria, including 1276 participants across athletic, injured, and non-active populations. Hip rotator ROM was measured in nine studies and strength in three, with varying testing angles (0° and/or 90° hip flexion). Overall, athletes showed greater ROM at 0° compared to injured and non-active groups, but had reduced ROM at 90° relative to non-active participants. Non-active individuals had the lowest ROM at 0°. Strength findings, though limited, indicated higher values at 90° than at 0°. Conclusions: Hip rotator ROM and strength vary across populations and testing angles, with ROM generally lower and strength higher at 90° of hip flexion. Due to methodological inconsistencies, findings should be interpreted as directional evidence, reinforcing the need for standardized assessment protocols in future research.
Assessments of hip joint strength and range of motion (ROM) are commonly employed for clinical evaluation of hip and groin pain [
1]. These assessments are utilized not only in athletic populations [
1,
2], but also in populations with hip pathologies such as hip osteoarthritis (OA) [
3,
4,
5,
6]. However, while research has extensively explored hip flexion, extension, and abduction, research specifically focusing on ROM and strength of hip rotator muscles remains limited.
The hip has been implicated as a contributing factor to inguinal pain, yet few publications or prevention programs specifically assess hip rotator function [
7]. In patients with patellofemoral pain (PFP), reduced hip abduction and external rotation (ER) strength are frequently observed, and an altered internal to external rotation (IR/ER) strength ratio has been proposed as a contributing factor [
8].
In athletic populations, femoroacetabular impingement (FAI) is recognized as a risk factor for early hip joint degeneration, with the typical injury mechanism involving combined hip flexion, adduction, and IR; movements that place substantial demand on the hip rotators [
9,
10]. Additionally, neuromuscular imbalances have been suggested as potential risk factors for these injuries [
11,
12]. Limited hip rotational capacity has also been identified as a contributing factor in the development of both FAI and anterior cruciate ligament (ACL) injuries [
13]. Despite growing interest, assessment strategies for hip IR and ER ROM and strength remain inconsistent across the literature.
To date, no systematic review has investigated how hip rotator strength and ROM vary across populations or how they are influenced by testing position. Clarifying these patterns is essential to guide screening, rehabilitation, and performance strategies. This systematic review aimed to investigate hip rotator ROM and strength values across different populations, specifically to determine whether (a) these values differ according to participant level of physical activity, and (b) whether they vary when measured using different hip flexion angles.
This entry is adapted from the peer-reviewed paper 10.3390/encyclopedia5040170
